Patent GB-617620-A (GB)
Title: Stabilised compositions containing polymers which evolve hydrogen chloride on decomposition
IPC: C08K5/138
Filed: 1946-05-02
Abstract: High molecular weight compounds which tend to split off hydrogen halide are stabilized by adding thereto a metal salt of a nuclearly substituted salicylic acid.  Compounds which may be so stabilized include polymers and copolymers of vinyl halides, vinylidene halides, halogenated styrenes, vinyl type esters of halogen-containing acids, and halogen-containing vinyl alcohol esters of organic acids; chlorinated polyvinyl chloride and polyvinyl ethers, chlorinated and brominated rubber, polymers and copolymers of chloroprene, fluoroethylene and chloroacrylic acid esters.  Particularly suitable salts are those of metals which allow the formation of chelate rings and include the normal, inner and basic salts of nickel, lead, beryllium, magnesium, calcium, strontium, cadmium and barium. Examples of groups which may be substituted in plurality or singly are alkyl and unsaturated hydrocarbon groups and groups containing oxygen.  Specified salts include the lithium, nickel, lead and alkaline earth metal salts of stearoyl salicylic, octadecyl salicylic, octyl salicylic and di-isopropyl salicylic acids; magnesium dibutyl and di-isopentyl salicylate, calcium oleoyl salicylate, barium palmitoyl salicylate, calcium 3-propyl-5-isopropyl salicylate, beryllium 3-isopropyl-5-valeryl salicylate, magnesium 3-isopropyl-5-allyl salicylate and lead tributyl salicylate.  The stabilizers are oil-soluble and compatible with plasticizers, other stabilizers, fillers, waxes and pigments.  Specifications 451,723 and 584,434 are referred to.ALSO:3,5-Di-isopropyl salicylic acid is prepared by slowly adding salicylic acid to a mixture of sulphuric acid and di-isopropyl ether maintained at 90 DEG -100 DEG  C. Heating at 95 DEG  C. is continued for 15 hours, the mixture cooled and the acid extracted with gasoline from which it is separated as a salt by the addition of caustic soda.  Acidification with sulphuric acid yields the acid. Salts prepared from approximately equivalent portions of metal and acid at temperatures below 140 DEG  C. are mainly basic.  Larger mol. portions of acid at low temperatures results in the normal salt; and on heating or by reactions above 140 DEG  C., the inner salts are mainly produced.ALSO:High molecular weight compounds which tend to split off hydrogen halide are stabilized by adding thereto a metal salt of a nuclearly substituted salicylic acid.  Compounds which may be so stabilised include chlorinated and brominated rubber, polymers and copolymers of chloroprene and other halogen-containing polymers (see Group IV). Particularly suitable salts are those of metals which allow the formation of chelate rings and include the normally basic and inner salts of nickel, lead, beryllium, magnesium, calcium, strontium, cadmium and barium.  Examples of groups which may be substituted in plurality or singly are alkyl and unsaturated hydrocarbon groups and groups containing oxygen. Specified salts include lithium, nickel, lead and alkaline earth metal salts of stearoyl salicylic, octadecyl salicylic, octyl salicylic and di-isopropyl salicylic acids; magnesium dibutyl and di-isopentyl salicylate, calcium oleoyl salicylate, barium palmitoyl salicylate, calcium 3-propyl-5-isopropyl salicylate, beryllium 3- isopropyl-5-valeryl salicylate, magnesium 3-isopropyl-5-allyl salicylate and lead tributyl salicylate.  The stabilisers are oil-soluble and compatible with plasticisers, other stabilisers, fillers, waxes and pigments.  Specifications 451,723 and 584,434, [both in Group IV] are referred to.